Receiving Device with Coil of Electric Line for Receiving a Magnetic Field and for Producing Electric Energy by Magnetic Induction and with Magnetizable Material

ABSTRACT

A receiving device for receiving a magnetic field and for producing electric energy by magnetic induction. The receiving device includes at least one coil of at least one electric line. The magnetic field induces an electric voltage in the at least one coil during operation. The receiving device and the at least one coil are adapted to receive the magnetic field from a receiving side of the receiving device. The receiving device includes a field shaping arrangement including magnetizable material adapted to shape magnetic field lines of the magnetic field. The field shaping arrangement is placed behind the at least one coil. A depth of the field shaping arrangement varies. A method of manufacturing a receiving device and an arrangement including the receiving device.

The invention relates to a receiving device for receiving a magneticfield and for producing electric energy by magnetic induction, inparticular for use by a vehicle. The invention also relates to a methodof manufacturing such a receiving device. In particular, the inventioncan be applied in the field of wireless transfer of energy to vehicles,such as road automobiles, busses, vans, trucks, but also load carriers,e.g. forklift trucks, and rail vehicles. The receiving device shall beadapted to produce electric power at least at rates in the kilowattrange, e.g. 20 kW.

WO 2012/010649 A2 discloses an arrangement for receiving anelectromagnetic field, for producing electric energy from theelectromagnetic field by induction and for providing a load with theelectric energy, in particular for providing a rail vehicle (e.g. atram) or a road vehicle with energy. For producing electric energy byinduction, the receiving arrangement comprises at least one inductorwhich may be realized by one or more windings of an electricalconductor. While a load is provided with electric energy from thereceiving arrangement, the resulting alternating current produced by theinductor is rectified. An output side of the rectifier is connected tothe load. The receiving arrangement may have three phases for receivingthe electromagnetic field and the rectifier may be connected to thethree phase lines of the receiving arrangement. Each phase comprises aninductance and a capacitance, which may be realized by in each case atleast one capacitor.

There is a demand for the integration of such a receiving device or adifferent receiving device in existing motor vehicles, such as roadautomobiles. The weight of the receiving device should be small, sincethe maximum revenue load of the vehicle should be affected as little aspossible. In addition, the construction of the receiving device and themounting of the receiving device should be stable and also easy toassemble. Existing spaces especially in the region of the bottom of thevehicle's car body should be utilized.

Typically, the magnetic field (as part of an alternating electromagneticfield) is produced by a device below the vehicle's bottom. Therefore,the receiving device which is typically mounted at the bottom of thevehicle receives the magnetic field from below, i.e. from the bottomside. However, it is possible to orient the receiving device in adifferent direction (such as the horizontal direction) if the magneticfield generating device is located in this direction. Generallyspeaking, the receiving device has a receiving side and, duringoperation, the magnetic field enters the receiving device or its case onthe receiving side.

EP 2081792 B1 discloses a cladding element having a receiving unitintegrated therein. The receiving unit comprises a receiver coil forcontactless transmission of electrical energy and a plurality of flowconducting elements that are allocated to the receiver coil and designedto concentrate the field strength and are made from a material havinghigh permeability compared with air.

Magnetizable material, such as iron or ferrite, can be used to shape thefield lines of the magnetic field. This may enhance field intensity atthe location of the coil or coils of the receiving device. Furthermore,the magnetizable material shields the surroundings of the receivingdevice, in particular the area beyond the magnetizable material ifviewed from the coil or coils. However, magnetizable material istypically heavy material which consequently increases the weight of thereceiving device.

It is an object of the present invention to provide a receiving deviceand a method of manufacturing a receiving device which comprisesmagnetizable material, wherein the weight of the receiving device issmall. In particular, the receiving device shall be mechanically stableand producible at small costs.

According to a basic idea of the present invention, the thickness of themagnetizable material, which is located behind the coil or coils,varies. “Behind” means that the magnetizable material is located inbetween the coil or coils and the side of the receiving device which isopposite to the receiving side. Alternatively, the thickness can benamed “depth”. The direction, in which the thickness or depth is to bemeasured, is the direction from the receiving side of the receivingdevice to the side of the receiving device opposite to the receivingside.

By varying the depth of the magnetizable material, weight can be saved.In particular, the depth of the magnetizable material can be chosen sothat the magnetizable material is deeper where necessary and less deepwhere sufficient. In particular, the depth of the magnetizable materialis designed to be larger at locations, if viewed from the receivingside, behind regions of the coil where the electromagnetic fieldproduced by electric currents through the at least one coil is largercompared to locations behind regions of the coil where theelectromagnetic field produced by electric currents through the at leastone coil is smaller. Provided that the field intensity of the magneticfield, which is produced by a generating device for transferring energyto the receiving device by induction and which enters the receivingdevice on the receiving side, is essentially constant along theextensions of the coil or coils, only the electric currents which areinduced in the coil or coils are responsible for variations of the fieldintensity behind the coil or coils.

In particular, the magnetizable material is arranged above the coil orcoils, if the receiving side is the bottom side. In any case, the fieldlines of the magnetic field enter the receiving device on the receivingside, penetrate the area covered by the coil or coils and arere-directed and bundled within the magnetizable material so as to returnto the field generating device.

Preferably, in the case of coils arranged to produce different phases ofan alternating current, the depth of the magnetic layer is larger behinda first region where coils of different phases overlap, and inparticular where electric lines of different coils overlap each other,compared to a second region where there is no overlap of coils ofdifferent phases or electric lines of different coils.

In particular, the outline of the field shaping arrangement, which isformed by the magnetizable material, may have a hat-like shape with adeeper central region and two less deep peripheral regions. Inparticular, the deeper central region is located behind regions of thecoil or coils having more parallel electric lines, thereby producing alarger electromagnetic field than the peripheral regions. In particular,the central region and the two less deep peripheral regions may form aplanar outline (i.e. an outline having no recesses or protrusions,except for gaps in between field shaping elements) on the side facingthe coil or coils.

In particular, the following is proposed: A receiving device forreceiving a magnetic field and for producing electric energy by magneticinduction, in particular for use by a vehicle, wherein

-   -   the receiving device comprises at least one coil of at least one        electric line and wherein the magnetic field induces an electric        voltage in the at least one coil during operation,    -   the receiving device and the at least one coil are adapted to        receive the magnetic field from a receiving side of the        receiving device,    -   the receiving device comprises a field shaping arrangement        comprising magnetizable material adapted to shape magnetic field        lines of the magnetic field,    -   the field shaping arrangement is placed behind the at least one        coil, if viewed from the receiving side of the receiving device,    -   a depth, to be measured in the direction from the receiving side        of the receiving device to the side of the receiving device        opposite to the receiving side, of the field shaping arrangement        varies.

Furthermore, proposed is: A method of manufacturing a receiving devicefor receiving a magnetic field and for producing electric energy bymagnetic induction, in particular for use by a vehicle, wherein

-   -   at least one coil of at least one electric line is provided,        wherein the at least one coil comprises an inductance, so that        the magnetic field induces an electric voltage in the at least        one coil during operation of the receiving device,    -   the coil is arranged to receive the magnetic field from a        receiving side of the receiving device,    -   a field shaping arrangement, comprising magnetizable material        adapted to shape magnetic field lines of the magnetic field, is        placed behind the at least one coil, if viewed from the        receiving side of the receiving device,        so that a depth, to be measured in the direction from the        receiving side of the receiving device to the side of the        receiving device opposite to the receiving side, of the field        shaping arrangement varies.

In particular, the receiving device may comprise a plurality of electriclines for carrying different phases of an alternating electric current.In addition or alternatively, the receiving device may comprise aplurality of coils, wherein coils of the same phase line may be arrangednext to each other and wherein coils of different phase lines mayoverlap each other. “Overlap” means that the magnetic field lines, whichenter the receiving device on the receiving side and which penetrate onecoil towards the side opposite to the receiving side, also penetrate theoverlapping coil(s).

In the following the expression “magnetic material” is used as a synonymof “magnetizable material”, although the magnetic state of the materialmay change. Preferably, the coil or coils of the receiving device is/arecombined with ferromagnetic and/or ferrimagnetic material (such as aferrite), which is arranged behind the coil or coils.

In particular, the area covered by the at least one coil includes thewhole area around which any winding of the coil or coils circulates.

In particular, a layer of electrically insulating material and/or ofelastic material can be arranged between the coil or coils and themagnetic material. In case of electrically conducting magnetic material,this layer insulates and in case of an elastic layer, mechanicvibrations and wear of the coils and the magnetic material isprohibited.

In particular, the field shaping arrangement is formed by a plurality offield shaping elements made of the magnetizable material. Using fieldshaping element facilitates forming the field shaping arrangements. Moreor less field shaping elements can be stacked so as to vary the depth ofthe field shaping arrangement. In particular, different field shapingelements can be placed next to each other, but leaving a gap in betweenthe neighboring field shaping elements, wherein the gap extends in adirection transverse to the direction of the depth. Consequently,magnetizable material can be saved and the weight is further reduced.Preferably, the gap or gaps are sized and are adapted to the depth ofthe field shaping arrangement according to the desired shielding effectof the magnetizable material. For example, the desired shielding effectcan be defined by a maximum value of the magnetic field behind the fieldshaping arrangement, if viewed from the coil or coils.

In particular, the field shaping elements may have equally large depthsand the depth of the field shaping arrangement varies, because differentnumbers of the field shaping elements are stacked upon each other in thedirection from the receiving side to the side opposite to the receivingside. Using field shaping elements having equally large depthsfacilitates forming the desired variation of the depth of the fieldshaping arrangement.

Preferably, variations of the depth of the field shaping arrangement arecompensated by at least one compensating element made ofnon-magnetizable material. It is preferred that the material of thecompensating element(s) is lighter in weight per volume compared to themagnetic material. “Compensation” means that the total depth of thecombined arrangement consisting of the field shaping arrangement and ofthe at least one compensating element varies less than the depth of thefield shaping arrangement. It is possible, but not preferred, that atleast one compensating element is arranged in between field shapingelements so as to form a combined stack of field shaping elements and atleast one compensating element. In this case, the depth of the fieldshaping arrangement is equal to the total depth reduced by the depth ofthe at least one compensating element. For example, the compensatingelement may be made of plastic, for example a polymer.

Compensating variations of the depth of the field shaping arrangementfacilitates the assembly of the receiving device. In particular, thereceiving device may comprise different layers and/or modules which arestacked upon each other. Similarly to the layer of electricallyinsulating material and/or of elastic material mentioned above, such alayer can be arranged behind the field shaping arrangement, if viewedfrom the coil or coils. Further layers may be a shield made ofelectrically conducting material for shielding an electric field and amodule comprising capacitors. Examples are given below. If thevariations of the depth of the field shaping arrangement would not becompensated, these layers and modules needed to be adapted to the depthprofile of the field shaping arrangement. Otherwise, mechanicalstability is at risk. Since it should be possible to produce receivingdevices with different depth profiles of the field shaping arrangement,this would require individually shaped parts for the respectivereceiving device. Therefore, the same type of additional layers andmodules can be used for different depth profiles, if the depthvariations are compensated.

Preferably, the variations of the depth are compensated so that thedepth of a combined arrangement consisting of the field shapingarrangement and of the at least one compensating element is constant.Due to this depth compensation it is possible to use planar layers,elements and modules in regions of the receiving device beyond themagnetic layer (if viewed from the coil or coils) and hollow spaces areavoided. Therefore, the receiving device can be compact and stable. Forexample, a layer of elastic material and/or a layer of electricallyconducting material (which therefore shields electromagnetic radiation)and/or a layer of electrically insulating material (which might be thebase plate of an electric circuit arrangement comprising the at leastone capacitor and connecting electric lines for connecting thecapacitor(s) and/or the coils to an external device may be placed on theregion which is formed by the magnetic material and the heightcompensating material.

In particular, the coil or coils comprise in each case at least onewinding of the electric line (in case of at least two phases: the phaselines) and the winding or windings of the respective coil defines acentral axis around which the electric line is wound. In particular, thewindings of the respective coil may circulate around an area in eachcase, wherein the area is substantially the same for each winding of therespective coil. Furthermore, it is preferred that all coils of thereceiving device have areas enclosed by the windings, which areas havesubstantially (with variations of only a few percent) the same size. Thecentral axis mentioned above penetrates the area at its center.Preferably, the coil or coils of the receiving device is/are flat, i.e.the winding or windings of each coil extend(s) in a plane and the planesof any different windings of the same coil are identical or parallel toeach other. In case of plural phases, sections of the electric lines ofat least one of the coils may extend outside of the plane due to thefact that electric lines of different coils and/or phases overlap eachother if viewed from the receiving side.

Preferably, not only the planes of different windings of the same coil,but also the planes of the windings of different coils are identical orparallel to each other so that the complete arrangement of the coils isflat, which means that the coils cover an area, which is penetrated bythe magnetic field during operation and which is significantly wider andlonger compared to the total height of the coil arrangement. Inparticular, the height may be smaller than ⅓, preferably one ⅕ and mostpreferred 1/10 of the width and length of the covered area.Consequently, the coil arrangement can be housed by a housing (or case)that is shaped like a flat box, i.e. a box having a small heightcompared to its width and length.

More generally speaking, the case has a flat configuration defining afirst surface on the receiving side and a second surface on the sideopposite to the receiving side, wherein the first surface and the secondsurface are connected by surface areas of the case which are oriented ineach case to another side than the receiving side and the side oppositeto the receiving side and which are smaller than the first surface andthe second surface.

In particular, at least one fastening and/or stiffening element in theshape of a column (preferably a plurality of columns) extending from thereceiving side to the opposite side may be part of the receiving device.The column(s) may be used to fix and/or separate different regions (inparticular the field shaping elements) of the magnetizable material ofthe field shaping arrangement. This facilitates mounting of the magneticmaterial and guarantees that the magnetic material remains inpredetermined desired positions and/or regions. Preferably, the at leastone column separates the different regions of magnetic material withrespect to a first direction (e.g. the transverse direction) andseparates different electric lines and/or bundles of electric lines withrespect to a second direction (e.g. the longitudinal direction), whereinthe first direction and the second direction may extend transverse toeach other, in particular perpendicularly to each other. The first andsecond direction may extend perpendicularly to the direction from thereceiving side to the opposite side of the receiving device.

At least one column of the separating structure may extend through a cutout of a material layer, which material layer is arranged on the sideopposite to the receiving side if viewed from the at least one coil.This layer may be made of elastic material. Alternatively or inaddition, the material of the layer may be electrically conducting orelectrically insulating. In any case, the column either holds the layeror, at least, limits movement of the layer.

At least one column of the fixing and/or separating structure may befixed to a base plate of the separating structure or of a case of thereceiving device, the base plate being preferably arranged on thereceiving side if viewed from the at least one coil. By fixing the atleast one column to the base plate, the column can be fixed in adesired, stable position. This facilitates assembling of the receivingdevice, since the column can be used for the assembly of othercomponents of the receiving device as separator or holding element.

Embodiments of the method of manufacturing the receiving device followfrom the description of the embodiments of the receiving device.

Examples of the invention will be described with reference to theattached drawing. The figures of the drawing show:

FIG. 1 an example of a case of a receiving device in a three dimensionalview,

FIG. 2 a view of a side face of the case shown in FIG. 1,

FIG. 3 an exploded view of the case shown in FIG. 1 and FIG. 2 with theinterior components of the receiving device, according to a specificembodiment, i.e. the interior components may be varied,

FIG. 4 an example of an arrangement of coils, in particular thearrangement shown in FIG. 3,

FIG. 5 a base part of the case shown in FIG. 1 and FIG. 2 with aspecific embodiment of an arrangement of components for positioningand/or fixing interior components of the receiving device,

FIG. 6 a layer of electrically insulating elastic material for coveringthe coil arrangement of a receiving device,

FIG. 7 schematically an intermediate layer of the interior of areceiving device, such as the layer shown in FIG. 6, and a plurality ofblocks made of magnetic material in an exploded view,

FIG. 8 schematically a side view of an arrangement of interiorcomponents of a receiving device, comprising a plurality of coils, anintermediate layer and an arrangement of magnetic material elements aswell as height compensating elements,

FIG. 9 a base plate made of electrically insulating material and anarrangement of capacitors and connecting lines in an exploded view,wherein the capacitors and connecting lines are to be positioned withina protruding portion of a case,

FIG. 10 an arrangement of the case shown in FIG. 1 and a rectifier,

FIG. 11 schematically a road vehicle and an arrangement for inductivelytransferring energy to the road vehicle, wherein a receiving device forreceiving a magnetic field is integrated at the bottom of the vehicle,

FIG. 12 schematically a cross section through a part of an arrangementsimilar to the arrangement shown in FIG. 5 in combination with thearrangement shown in FIG. 7 and

FIG. 13 schematically a cross section through a part of an arrangementsimilar to the arrangement shown in FIGS. 4 and 5 in combination withthe arrangement shown in FIG. 7, wherein the image plane of FIG. 13extends perpendicularly to the image plane of FIG. 12.

The receiving device 1 shown in FIG. 1 and FIG. 2 comprises a casehaving a base plate 2 and a top part or cover 3. While the base plate 2forms a planar surface on the underside (the receiving side of thereceiving device to be housed by the case), the top surface formed bythe cover 3 is not planar as a whole, but only comprises planar regions.The cover 3 has three elongated protruding portions 5, 6 a, 6 b whichprotrude to the top side (the side opposite to the receiving side of thecase or receiving device).

In the embodiment shown in FIG. 1 and FIG. 2, the cover 3 forms the mainsections of the side surfaces of the case 1. In alternative embodiments,the case may comprise more than two parts forming the outer surfacesand/or larger parts of the side surfaces may be formed by the base partwhich corresponds to the base plate 2 in FIG. 1 and FIG. 2.

As shown in FIG. 1, the side surfaces of the case comprise a pluralityof means for fixing the case 1 to a vehicle, in particular to a frameconstruction of the vehicle. For example, the fixing means 8 may bethreaded holes for screwing the case to the vehicle.

The protruding portions 5, 6 a, 6 b of the cover 3 are elongated, i.e.in each case comprise a longitudinal axis along which they extend.Preferably, the protruding portions extend along the whole length of thecase and preferably have the same profile along their extension inlongitudinal direction.

The protruding portion 5 is located in the center of the case (if viewedin width direction) and extends along the center line of the case, i.e.in lengthwise direction of the case. The cross section of the protrudingportion 5 is trapezoidal, wherein the cross section tapers to the freetop end of the protruding portion 5.

According to the specific embodiment shown in FIG. 1 and FIG. 2, thecentral protruding portion 5 has an opening in the side face shown inFIG. 2 which opens to a tubular connecting part 7 that can be used forreceiving electric connection lines or cables.

Variations of the embodiment shown in FIG. 1 and FIG. 2 are possible,such as a case having the protruding portion 5 along the center line,but does not have the side protruding portions 6 a, 6 b or only havingone of these side protruding portions.

The exploded view of FIG. 3 shows a specific embodiment of a receivingdevice, wherein the components of the receiving device are housed by thecase shown in FIG. 1 and FIG. 2.

The base part 2 of the case carries a holding device 12 for holdingother interior components of the receiving device, in particularelectric lines that form in each case two coils of three phases. Inaddition, the holding device 12 comprises a plurality of columns forseparating, holding and/or fixing components of the receiving devicewhich are located above the coils. In particular, at least oneintermediate layer of insulating and/or elastic material, magneticmaterial, a layer of electrically conducting shield material and/or abase plate for an electric circuit arrangement can be separated, heldand/or fixed using one or more than one of the columns.

When the cover 3 of the case is mounted to the base plate 2 of the case,the outer rim of the cover 3 abuts on a sealing 11 which is positionedin the periphery of the holding device 12 and is supported by the rim ofthe base plate 2.

A coil arrangement 31 is positioned within pre-defined receiving spacesof the holding device 12. Since the different electric lines (phaselines) for producing the different phases of an alternating current formcoils which overlap each other if viewed from the top (from the cover3), the phase lines of at least two of the phases rise nearby thelongitudinal sides of the coil arrangement so that they extend along thelongitudinal side one upon the other, where they overlap. Details of aspecific embodiment of this kind are shown in FIG. 4 and will bedescribed later.

The coil arrangement 31 is covered by a layer 51 of elastic materialwhich is preferably also electrically insulating. The layer 51 may beformed by a single piece of material or by a plurality of pieces.

An arrangement 61 of magnetizable material, in particular ferrimagneticmaterial or alternatively ferromagnetic material, is placed on theintermediate layer 51. Preferably, the height (i.e. the depth) of themagnetic material differs and is larger above (i.e. behind) regionswhere the density (number per length) of the electric lines of the coilarrangement 31 is higher.

Preferably, compensating material 71 is placed where the height of themagnetic material 61 is smaller so that the height of the totalarrangement of magnetic material 61 and compensating material 71 isconstant or, at least, varies less than the height of the magneticmaterial 61.

In the specific embodiment shown in FIG. 3, a second intermediate layer81, which may be have the features described above for the intermediatelayer 51, is placed on top of the magnetic material 61 or thecompensating material 71.

A shielding layer 91 made of electrically conducting material, forexample aluminum, is placed on top of the second intermediate layer 81.The shielding layer 91 has cut outs 95 so that at least some of thecolumns of the holding device 12 can extend through the cut outs 95.Some cut outs or regions 96 of the cut outs can be used for placingsections of electric connections between the coil arrangement 31 and theelectric circuit 111 that is placed above the shielding layer 91.

The circuit arrangement 111 is placed on a sheet-like carrier 101, suchas a conventional circuit board. There is a cut out 100 in the carrier101 so that electric connections between the circuit arrangement 111 andthe coil arrangement 31 can extend through the cut out 100.

In the specific embodiment shown in FIG. 3, the carrier 111 and theshielding layer 91 comprise bores 97 or other cut outs which allow forfixing the carrier 101 to columns of the holding device 12 so that thecomplete arrangement of interior components of the receiving device isfixed to the holding device 12. In particular, the electric circuitarrangement 111 can be fixed to the carrier, for example by soldering,and the holding device 12 can be fixed to the base plate 2 of the case,such as by gluing or screwing. Preferably, screws are also used to fixthe carrier 101 to the columns of the holding device 12.

A preferred embodiment of the coil arrangement 31 is shown in FIG. 4.The coil arrangement consists of six coils 33 a, 33 b, 35 a, 35 b, 37 a,37 b, two coils per phase line 32, 34, 36. The coils of each phase lineare placed next to each other on the same height level of the receivingdevice. FIG. 4 shows an exploded view of the coil arrangement 31.

To form the two coils of one phase, the respective phase line 32, 34, 36is wound starting at one end of a first coil around the area to becovered so as to form the first coil and further extends around the areato be covered by the second coils so as to form the second coil. In theexample shown in FIG. 4, each coil may comprise two to five windings.The number of the windings of the phase lines 32, 34, 36 is not shown inthe figures.

As mentioned before, the coils of the different phases overlap eachother partially in the middle region of the coil arrangement 31. Thephase lines 32, 34, 36 are placed one upon the other where the coilsoverlap. Since transversally extending sections of the different phaselines 32, 34, 36, which sections connect the longitudinal sides, areplaced on the same height level in the finished coil arrangement 31, atleast the phase lines 34, 36 rise along their extension next to thelongitudinal sides of the coils. The holding device 12 defines spacesfor receiving these transversely extending sections of the phase lines,wherein the spaces are on the same height level.

Although the phase lines 32, 34, 36 are preferably electricallyinsulated at their surfaces, the coils 33, 35, 37 of the differentphases are preferably placed upon each other using distance pieces 41,42, 43. These pieces are placed in between the phase lines 32, 34, 36where they are placed one upon the other. In particular, there are threetypes of distance pieces. The first type 41 is used where the phase line34 of the second phase is placed above the phase line 32 of the firstphase along the longitudinal side of the coil arrangement 31. The firsttype 41 of distance pieces is elongated and extends along thelongitudinal side and, at the same time, along the phase lines 32, 34 soas to form a distance between the phase lines 32, 34. The first type 41of the distance pieces has a constant cross section. It is used for thesecond coil 33 b of the first phase.

The second type 42 of distance pieces does not have a constant crosssection, but the end region shown on the right hand side of FIG. 4 issignificantly higher than the other sections. Where the distance pieces42 are higher, the first coil 33 a of the first phase supports the firstcoil 37 a of the third phase. Where the height of the distance pieces 42is smaller, the first coil 33 a of the first phase supports the firstcoil 35 a of the second phase.

The third type 43 of the distance pieces also has a non-constant,varying cross section. The end regions of the distance pieces 43 arehigher than the other regions. Where the height is larger, the secondcoil 35 b of the second phase supports other components of the receivingdevice which are placed above the coil arrangement 31. Where the heightof the distance pieces 43 is smaller, the second coil 35 b or the firstcoil 35 a of the second phase supports the first or second coil 37 a, 37b of the third phase.

In particular, the number of the distance pieces 41, 42, 43 depends onthe number of windings per coil. Since the number of windings may differin different embodiments of the arrangement, FIG. 4 shows differentnumbers of the different types of the distance pieces 41, 42, 43.However, in practice, it is preferred that all coils comprise the samenumber of windings and, consequently, that the numbers of the differenttypes of distance pieces are equal.

The longitudinal section of the coil 33 b of the first phase is fullyoverlapped by the coils 35 a, 35 b of the second phase. If the coils 35a, 35 b are placed on top of the coils 33 a, 33 b, the transverselyextending section at the side face of coil 35 b is placed outside of thearea which is covered by the second coil 33 b of the first phase. Thetransversely extending section of the second phase which comprisessections of the first coil 35 a and the second coil 35 b is placed inthe area around which the phase line 32 of the second coil 33 b of thefirst phase extends. The transversely extending section of the firstcoil 35 a of the second phase is placed in the area around which thephase line 32 of the first coil 33 a of the first phase extends. Thecorresponding arrangement can be perceived from FIG. 3: the transverselyextending sections of the coils are separated from the neighbouringtransversely extending section of another coil in each case by at leastone of the columns. In the example shown, there are five columns in eachcase in between two neighbouring transversely extending sections.

The coils 35 of the second phase and the coils 37 of the third phase areshifted in a similar manner relative to each other as the first phaseand the second phase, but the shift length in longitudinal direction istwice as large as the shift length of the first and second phase. As aresult, the transversely extending section at the side face of the firstcoil 37 a of the third phase is placed outside of the area around whichthe phase line 32 of the first coil 33 a of the first phase extends. Onthe other hand, the shift length in longitudinal direction of the thirdphase relative to the first phase has the same amount as the shiftlength of the first phase and the second phase, but is oriented in theopposite direction if viewed from the first phase coil arrangement.

At least one end of the phase line 32, 34, 36 which forms the coils ofthe respective phase is connected to a line section or forms a linesection that extends upwards from the coils. Respective upwardlyextending sections 38, 39, 40 are shown in FIG. 4. The other ends of thephase lines 32, 34, 36 can directly be connected to each other (notshown in FIG. 4) so as to form an electrical star point. Since at leastone end of each phase line 32, 34, 36 is connected to an upwardlyextending section 38, 39, 40, the coil arrangement can be electricallyconnected in a different region (in particular on a higher level) of thereceiving device, in particular to components which are located in theprotruding portion of the case. In particular, the upwardly extendingsections 38, 39, 40 are connected to in each case at least one capacitorof the circuit arrangement 111 shown in FIG. 3 and FIG. 9.

The enlarged view of the base plate 2 and the holding device 12 shown inFIG. 5 comprises a plurality of columns 13, 14, 15 which extend upwardsfrom the basis of the holding device. A preferred material of theholding device 12 is plastic, such as a polymer. Preferably, the basisof the holding device 12 is sheet-like forming a planar or merely planarouter surface facing to the base plate 2. Preferably, the columns 13,14, 15, the basis and optionally further portions (e.g. holding portionsfor holding electric lines or bundles of electric lines) of the holdingdevice 12 are formed as an integral part, for example by injectionmoulding. Alternatively, at least one of the columns 13, 14, 15 can bemanufactured as a separate piece and can be fixed to the basis.

The holding device 12 comprises holding portions 16, 17 for holdingelectric lines or bundles of electric lines. Depending on the number ofthe electric lines or bundles of electric lines to be held by theindividual holding portion 16, 17, the holding portions are wider ornarrower (with respect to the longitudinal direction). In the exampleshown in FIG. 5, the first three holding portions 16 from the left andfrom the right in the figure are narrower than the three holdingportions 17 in the middle.

The columns 13, 14, 15 are arranged in lines extending in thelongitudinal direction (from left to right in FIG. 5) and rows extendingin transverse direction (from front to back in FIG. 5). There are spacesin between the rows of columns and beyond the first and last row,wherein these spaces are adapted to receive the respective transverselyextending sections of the coils of the coil arrangement, in particularthe coil arrangement 31 as shown in FIG. 4. In the specific embodimentshown in FIG. 5, the width of these spaces as measured in thelongitudinal direction differs corresponding to the number of sectionsof electric lines which are to be placed side by side to each other onthe same height level. Consequently, in view of the coil arrangement 31shown in FIG. 4, the first three spaces have a smaller width which is inparticular half as wide as the width of the three spaces in the middleof the holding device 12.

The lines of the columns 13, 14, 15 are spaced so that pieces ofmagnetic material and optionally compensating material can be placed inbetween in each case two of the columns.

In addition, at least one of the columns 13, 14, 15 can be used forfixing other components of the receiving device to the column andthereby to the holding device 12.

Therefore, the columns combine different functions, in particularseparating different transversely extending sections of coil, separatingdifferent pieces of material, such as magnetic material and compensatingmaterial, and/or fixing other components to the respective column. Afurther possible function is separating components of the receivingdevice from the basis of the holding device and/or from the basis of thereceiving device at the receiving side. “Separating” means that therespective components or parts cannot contact each other. The respectivedimension of the column, either in longitudinal direction, in transversedirection or in height direction, defines the minimum distance betweenthe two parts or components which are separated.

In addition, as mentioned before, the specific embodiment of the holdingdevice 12 shown in FIG. 5 comprises elevated rims 18 along thelongitudinal sides. In any case, the rims of the holding device alongthe longitudinal sides are adapted to receive the corresponding sectionsof the coil arrangement.

Preferably, the spaces for receiving the phase lines of the coilarrangement have shaped surfaces, in particular grooved surfaces, sothat the phase lines are held in place and do not slip. In particular,these spaces can be provided by holding portions of the holding device.

In particular, two columns 15 of the holding device 12 are higher thanthe other columns 13, 14 and serve to position and/or fix the carrier101 and the circuit arrangement 111 shown in FIG. 3 and FIG. 9.

The intermediate layer 51 (and optionally the intermediate layer 71)shown in FIG. 3 are shaped as shown in FIG. 6. The layer 51 may be madeof an elastic material, such as silicone. The layer 51 comprises aplurality of cut outs 23, 24, 25 which are arranged in lines and rowssimilarly to the lines and rows of the columns 13, 14, 15 of the holdingdevice 12. Preferably, the cut outs 23, 24, 25 are sized so that thecolumns may extend through the cut outs while abutting to the surfacesof the cut outs 23, 24, 25. It is preferred that the surfaces of the cutouts 23, 24, abut to the surface of the respective column 13, 14 allaround the column. In the center line of the receiving device and,therefore, of the layer 51, there is the cut out 25 which has a lengththat is larger than the length of the columns 15. This allows forpassing other components through the cut out 25. In particular, theupwardly extending line sections 38, 39, 40 shown in FIG. 4 may extendthrough the cut out 25.

FIG. 7 and FIG. 8 schematically show the arrangement of a plurality ofmagnetic material pieces 62 (e.g. pieces having the shape of a cuboid)which is to be placed on an intermediate layer 51 which may be theintermediate layer 51 shown in FIG. 6. However, the number of cut outs23, 24 and their shapes may vary from embodiment to embodiment. Inaddition, the arrangement can be used with a different type of receivingdevice as described with reference to the figures. FIG. 7 and FIG. 8show the principle of placing magnetic material above the coilarrangement of a receiving device, independent of the interiorcomponents used in the receiving device and independent of the specificdimensions of the interior components of the receiving device.

In FIG. 7, areas 63 where magnetic material pieces 62 are to be placedare indicated by dashed outlines. For a first line of such areas 63, thepieces 62 are shown in the exploded view of FIG. 7. There are fourpieces 62 to be placed on top of the two areas 63 in the middle of theline and there are only two pieces 62 to be placed on the two areas 63at the end of the line. The resulting stacked arrangement of pieces 62is schematically shown in FIG. 8. Since all pieces 62 have the samedimensions, the two stacks in the middle are twice as high as the twostacks at the opposite ends of the line. The motivation for thesedifferent total heights of magnetic material is the overlap of thedifferent phase lines 32, 34, 36 which form the coils of the differentphases, for example as shown in FIG. 4. Higher magnetic field strengthscaused by more electric lines require more magnetic material.

In order to compensate for the different heights of the magneticmaterial, compensating material 72 is placed as shown in FIG. 8.

FIG. 7 also shows the cut outs 23, 24 and that the lines of areas wherethe magnetic material is to be placed are located in between the linesof the cut outs 23, 24. In longitudinal direction, it is preferred thatthe magnetic material pieces 62 abut to each other (in contrast to thesmall distances shown in FIG. 8). As preferred, at least one column (notshown in FIG. 7) and preferably a plurality of columns extend(s) in eachcase through one of the cut outs 23, 24, thereby separating the lines ofthe magnetic material pieces 62.

Variations of the embodiment of a field shaping arrangement shown inFIG. 7 and FIG. 8 are possible. In particular, it is not necessary tocombine the arrangement with one of the intermediate layers or any ofthe intermediate layers shown in FIG. 6. Furthermore, the columns can beomitted. In addition, the shape of the elements made of magnetizablematerial may be different. However, shapes are preferred which allow forproducing a mosaic of elements having seams between the elements, but noother hollow spaces.

FIG. 9 shows an enlarged view of the carrier 101 and of the electriccircuit arrangement 111 which is carried and preferably fixed on thecarrier 101. There is a plurality of block-shaped capacitors 115, someof which are electrically connected to each other by plate-likeelectrical connectors 116. In addition, the capacitors 115 areelectrically connected to the respective coil in particular via theupwardly extending connecting sections 38, 39, 40 shown in FIG. 4 andare electrically connected via connection lines 112, 113, 114 to anexternal device, in particular to the rectifier 120 shown in FIG. 10.These external connection lines 112, 113, 114 can be guided through theconnecting part 7 shown in FIG. 1 and FIG. 2.

At least the upper part of the circuit arrangement 111 shown in FIG. 9can be placed within the protruding portion 5 of the cover 3 of the caseshown in FIG. 1 and FIG. 10. The protruding portions 6 a, 6 b of thecover 3 along the longitudinal sides are preferably used for receivingat least sections of the phase lines and optionally of the spacingpieces of the coil arrangement, such as the circuit arrangement 31 shownin FIG. 4.

FIG. 10 shows the receiving device 1 of FIG. 1 and a rectifier 120 whichis housed by a housing 121. In particular, the connecting lines 112,113, 114 shown in FIG. 9 connect the receiving device 1 with therectifier 120.

The central protruding portion 5 of the receiving device 1 is elongatedand extends along a longitudinal axis which is also the longitudinalaxis of the housing 121 of the rectifier 120. This arrangement can beplaced in corresponding recesses formed by the bottom surface of the carbody of a road vehicle. Such a road vehicle 141 is shown in FIG. 11. Thelocation of the receiving device is schematically indicated by a blockwith reference numeral 143 and the location of the rectifier isschematically indicated by a block with reference numeral 144.

During energy transfer to the vehicle, a generating device 142 generatesthe magnetic field, in particular by generating an alternatingelectromagnetic field. The magnetic field is indicated by three curvedlines. The generating device 142 is provided with electric current fromcorresponding equipment 145, which may include an inverter and/or anAC/AC converter.

FIG. 12 shows five columns 13, 15 which extend upwards from a base plateof a separating structure 12, wherein the receiving side of thereceiving device is at the bottom of the figure. A layer 51 of elasticmaterial extends at a distance and parallel to the base plate. In asimilar manner as shown in the exploded view of FIG. 8, pieces ofmagnetic material 62 are laid on the layer 51 in between the columns 13,15. Consequently, the columns 13, 15 separate the pieces of magneticmaterial 62. In addition, the columns 13, 15 extend through cut outs ofthe layer 51.

FIG. 13 shows three columns 13, 14, 15 which extend upwards from a baseplate of a separating structure 12, wherein the receiving side of thereceiving device is at the bottom of the figure. In the same manner asshown in FIG. 12, the layer 51 of elastic material extends at a distanceand parallel to the base plate. While FIG. 12 shows a region of thearrangement where no electric lines of the coil arrangement arepositioned in between the base plate and the layer 51, FIG. 13 shows aregion of the arrangement where bundles of electric lines, in particularthe phase lines 34, 36 of the arrangement shown in FIG. 4, of the coilarrangement are positioned in between the base plate and the layer 51.The bundles are held by holding portions 16, 17 of the separatingstructure 12. The holding portions 16, 17 in each case form a groove forreceiving the electric lines 34, 36. In case of the receiving portions16, there are three electric lines 36 side-by-side in the groove. Incase of the receiving portions 17, there are five electric lines 34side-by-side in the groove. In alternative embodiments, the electriclines may be held in a different manner, for example using a groove foreach single electric line and/or with electric lines not or not onlyside-by-side in the longitudinal direction (horizontal direction in FIG.13), but stacked. Consequently, the column 15 separates the holdingportions 16, 17 and thereby the bundles of electric lines 34, 36. Inaddition, the column 15 extends through a cut out of the layer 51.

Modifications of the arrangement shown in FIG. 12 and FIG. 13 arepossible. For example, the numbers and/or dimensions of the elements andcomponents shown in the figures may vary. In addition, the columns maybe used for separating, holding and/or fixing other components of thereceiving device in addition to the components shown in the figures oralternatively to the at least a part of the components shown in thefigures.

1. A receiving device configured to receive a magnetic field and toproduce electric energy by magnetic induction, wherein the receivingdevice comprises at least one coil of at least one electric line andwherein the magnetic field induces an electric voltage in the at leastone coil during operation, the receiving device and the at least onecoil are adapted to receive the magnetic field from a receiving side ofthe receiving device, the receiving device comprises a field shapingarrangement comprising magnetizable material adapted to shape magneticfield lines of the magnetic field, the field shaping arrangement isplaced behind the at least one coil, if viewed from the receiving sideof the receiving device, a depth, to be measured in a direction from thereceiving side of the receiving device to a side of the receiving deviceopposite to the receiving side, of the field shaping arrangement varies,wherein a depth of the magnetizable material is larger at locations, ifviewed from the receiving side, behind regions of the at least one coilwhere the electromagnetic field produced by electric currents throughthe at least one coil is larger compared to locations behind regions ofthe at least one coil where the electromagnetic field produced byelectric currents through the at least one coil is smaller. 2.(canceled)
 3. The receiving device of claim 1, wherein the field shapingarrangement is formed by a plurality of field shaping elements made ofthe magnetizable material.
 4. The receiving device of claim 3, whereinthe field shaping elements have equally large depths and wherein thedepth of the field shaping arrangement varies, because different numbersof the field shaping elements are stacked upon each other in thedirection from the receiving side to the side opposite to the receivingside.
 5. The receiving device of claim 1, wherein variations of thedepth of the field shaping arrangement are compensated by at least onecompensating element made of non-magnetizable material.
 6. The receivingdevice of claim 5, wherein the variations of the depth are compensatedso that a depth of a combined arrangement consisting of the fieldshaping arrangement and of the at least one compensating element isconstant.
 7. A method of manufacturing a receiving device configured toreceive a magnetic field and to produce electric energy by magneticinduction, wherein at least one coil of at least one electric line isprovided, wherein the at least one coil comprises an inductance, so thatthe magnetic field induces an electric voltage in the at least one coilduring operation of the receiving device, the coil is arranged toreceive the magnetic field from a receiving side of the receivingdevice, a field shaping arrangement, comprising magnetizable materialadapted to shape magnetic field lines of the magnetic field, is placedbehind the at least one coil, if viewed from the receiving side of thereceiving device, so that a depth, to be measured in a direction fromthe receiving side of the receiving device to a side of the receivingdevice opposite to the receiving side, of the field shaping arrangementvaries, wherein a depth of the magnetizable material is designed to belarger at locations, if viewed from the receiving side, behind regionsof the at least one coil where the electromagnetic field produced byelectric currents through the at least one coil is larger compared tolocations behind regions of the at least one coil where theelectromagnetic field produced by electric currents through the at leastone coil is smaller.
 8. (canceled)
 9. The method of claim 7, wherein thefield shaping arrangement is formed by a plurality of field shapingelements made of the magnetizable material.
 10. The method of claim 9,wherein field shaping elements are used which have equally large depthsand wherein the depth of the field shaping arrangement is varied bystacking different numbers of the field shaping elements upon each otherin the direction extending from the receiving side to the side oppositeto the receiving side.
 11. The method of claim 7, wherein variations ofthe depth of the field shaping arrangement are compensated by at leastone compensating element made of non-magnetizable material.
 12. Themethod of claim 11, wherein the variations of the depth are compensatedso that a depth of a combined arrangement consisting of the fieldshaping arrangement and of the at least one compensating element isconstant.